Process for mounting lugs and/or projections on a thin metal sheet and a thin metal sheet having lugs and/or projections as well as a rectangular tube made of thin metal sheets

摘要

A process for mounting lugs or projections on a thin metal sheet, by forming the lugs and/or projections out of the thin metal sheet by way of massive forming. Such a thin metal sheet in the form of a thin sheet metal strip is used preferably for forming rectangular tubes for an exhaust gas heat transfer device which, for guiding the exhaust gas, is provided with a bundle of these rectangular tubes.